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Silverzedtom wrote: ↑Sat Feb 09, 2019 10:40 am I Picked up a solar charger a couple of weeks ago when my old battery bit the dust. No cables to worry about no good inside of course

best way. even in winter it will keep the battery happy and topped up - much better than battery chargers - the ultimate trickle charger

This looks an interesting development:

https://www.baintech.com.au/ctek-battery-sense

for those that still want a charger.. saw this today in aldi.. looked alright too !

With an modern alternator throwing out 100 amps it doesn’t take long to replenish a battery to 100% if the car is used for few times a week - I would say a trickle charger is only needed if laying up over winter etc.

road warrior wrote: ↑Sun Feb 10, 2019 10:48 pm for those that still want a charger.. saw this today in aldi.. looked alright too !

I have one of these. Very well made, the clips are reassuringly solid. It's incredibly easy to use and set up. Keeps the battery at perfect charge. It does everything a much more expensive CTEK can and comes with a three year warranty from Aldi (no dealing with Hong Kong Harry on eBay).

So, frankly, I just don't understand why anyone would buy a CTEK over this. In my opinion a bargain for £12.99.

JamieZ4C wrote: ↑Mon Feb 11, 2019 8:36 am

road warrior wrote: ↑Sun Feb 10, 2019 10:48 pm for those that still want a charger.. saw this today in aldi.. looked alright too !

I have one of these. Very well made, the clips are reassuringly solid. It's incredibly easy to use and set up. Keeps the battery at perfect charge. It does everything a much more expensive CTEK can and comes with a three year warranty from Aldi (no dealing with Hong Kong Harry on eBay).

So, frankly, I just don't understand why anyone would buy a CTEK over this. In my opinion a bargain for £12.99.

I know lots of Zed's run more modern batteries now so it's worth noting that the Aldi Auto XS is for LEAD ACID batteries only. It's great value but doesn't actually have all the features of a CTEK and most of the google results that come up relate to the units prematurely failing, so I guess you pays your money....

Aldi Auto XS manual https://manualzz.com/doc/4176885/aldi-a ... r-s-manual

Ewazix wrote: ↑Mon Feb 11, 2019 9:08 am

JamieZ4C wrote: ↑Mon Feb 11, 2019 8:36 am

road warrior wrote: ↑Sun Feb 10, 2019 10:48 pm for those that still want a charger.. saw this today in aldi.. looked alright too !

I have one of these. Very well made, the clips are reassuringly solid. It's incredibly easy to use and set up. Keeps the battery at perfect charge. It does everything a much more expensive CTEK can and comes with a three year warranty from Aldi (no dealing with Hong Kong Harry on eBay).

So, frankly, I just don't understand why anyone would buy a CTEK over this. In my opinion a bargain for £12.99.

I know lots of Zed's run more modern batteries now so it's worth noting that the Aldi Auto XS is for LEAD ACID batteries only. It's great value but doesn't actually have all the features of a CTEK and most of the google results that come up relate to the units prematurely failing, so I guess you pays your money....

Aldi Auto XS manual https://manualzz.com/doc/4176885/aldi-a ... r-s-manual

Hi the mode lablelled * on the Lidl charger is for AGM mode..

Given the fact that the average Lidl car owner won't know about AGM vs Flooded you can rely on the Lidl one doing an acceptablee job for both types..

This version is an iteration of the two models I use..I have not incurred any catastophic failures using them..

AGM is still lead acid! The Aldi / Lidl chargers look to be good value for money. Most of the bad reports seem to be focus on the fact that the charger doesn't re-start if you get a brief power cut mid charge and also seems to be a bit hit and miss at knowing when to terminate the charge. I suspect the latter is when using with a less than optimal battery.

ph001 wrote: ↑Mon Feb 11, 2019 10:33 am AGM is still lead acid! The Aldi / Lidl chargers look to be good value for money...........

You are absolutely right of course AGM is a type of lead acid battery, but the point I was making is that AGM requires a different charge cycle which is usually catered for by a setting on chargers that have that facility, or can automatically adjust. e.g. not all CTEK models are advertised as suitable for AGM. If the AldiI/Lidle units do then great, but it's certainly worth checking and getting an authoritative answer before ruining an expensive AGM with a bargain charger.

The charger I have will deal with powercuts. As it kicks in and monitors the battery even when not plugged in. I tested it

The vast majority of smart chargers on the market charge in 3 primary modes:

1) Bulk charge mode
This is where the output voltage is undefined and the charger just dumps as much current into the battery as it can, causing the battery voltage to rise slowly. This mode continues until the voltage reaches a pre-determined point. For normal lead acid it is typically around 14.4V, for AGM it is around 14.7V. At this point that battery will be approx 80% charged.

2) Absorption mode
This is where the voltage is held constant (14.4V or 14.7v) and the charge current gradually decreases to a low value. The actual end value for the current is dependent on many factors such as battery size, chemistry and amount of leakage. The decent quality chargers like the Ctek look at delta I, that is to say they look at the RATE of decrease of current. When it has stopped decreasing by less than 1% of the previous period, the battery is considered 100% charged.

Cheaper chargers just look for the current dropping below a set level, usually about 100mA - sometimes that condition is never met (particularly if the battery is still connected to the car as ancilliary items can draw current and trick the charger) and the charger stays locked in absorption mode and causes grid corrosion on the positive plate, i.e. it overcharges it. Any half decent design would have a time-out limit to prevent this.

3) Float mode
When the charge current has dropped as per the previous stage, the battery charge voltage is reduced to a float voltage (typically 13.5V for flooded and 13.8V for AGM), which is the highest long term voltage that can be applied without causing grid corrosion & gassing on the positive plate whilst also being sufficiently high so as not to cause sulfation on the negative plate. Some better chargers (again like the Ctek) monitor the battery voltage and use a pulse of current over a very short period of time to keep the float level maintained rather than apply a constant float voltage. This has the benefit of 'excercising' the battery a little and helps to keep the plates in top condition.

It is important to note that all the voltages above should be modified in proportion to ambient temperature - the charge voltage should be reduced by 18mV for every degree above 25°C and increased by 18mV for every degree below 25°C.

Many chargers don't measure temperature so have a 'winter' setting instead which raises the charge voltage by around 0.4V (simulating 5'C ambient).


Other modes
There are chargers that also do boost or equalization cycles which apply a much higher voltage at a controlled current and duration which can help to regen sulphated plates and stir up any stratified electrolyte in flooded lead acid batteries. It is likely to be of limited effect on heavily sulphated plates without a very large equalization current (tens of amps) which smaller chargers are not capable of providing. AGM batteries do not suffer from this so should never be equalized.


Can I use a normal lead acid smart charger on an AGM battery?

Because of the suitably different charging voltages, most people will tell you that a normal lead acid charger is no good for AGM. In practice though we see that the worst case scenario is that the absorption mode voltage is a little below that required to get 100% charge into the battery (but still good enough for perhaps 95%). There is certainly no risk of overcharging (grid corrosion on the positive plate).

Some would argue that if the battery is stored for many months at a float voltage of 13.5V instead of the optimal 13.8V, it will lead to plate sulfation. In reality, the amount of sulfation would be so small it would take many years to have any noticeable effect. In any case, proper battery temperature compensation equates to more than 300mV in the 5 - 30'C range and most chargers don't do this at all! Choosing a winter setting can minimise any potential issues even more.

Also, remember that new lead acids are often sat on manufacturers and distributors shelves for many months at their fully charged voltage of 12.7V with no significant degradation (they are supposed to be checked and topped up every 6 months). Again, AGM have lower self discharge to have an additional benefit in this respect.

Thanks ph001 for posting that detailed explanation
I think the moderators should consider making it a sticky for future reference .

I was losing power to open roof from key mainly due to little use of the car so I purchased a £20 trickle charger from Argos and problem easily solved . I boost it now once in a while and no further issues.

I left my car a month ago outside in sunny California with a solar trickle charger in the rear window, wires routed outside to the battery in the trunk. Will see end of this month if that did the trick(le)!

road warrior wrote: ↑Mon Feb 11, 2019 11:05 pm The charger I have will deal with powercuts. As it kicks in and monitors the battery even when not plugged in. I tested it

The Aldi / Lidl chargers definitely DO NOT auto restart after a power cut as you have to press the button to select the mode each time after the mains has gone off. Yours must be a slightly better one if it does.